The present invention relates to methods and apparatus for controlling a vehicle component, system or subsystem based on occupancy of a seat. The occupancy of the seat can be reflected in a property or state of the occupant of a seat and the position of the seat.
The vehicle component, system or subsystem, hereinafter referred to simply as a component may be a system such an as airbag system, the deployment or suppression of which is controlled based on the occupancy of the seat and/or location of the seat. The component may also be an adjustable portion of a system the operation of which might be advantageously adjusted based on the occupancy of the seat and/or the location of the seat, such as a device for regulating the inflation or deflation of an airbag that is associated with an airbag system.
In addition, the component may be any adjustable component of the vehicle including, but not limited to, the bottom portion and backrest of the seat, the rear view and side mirrors, the brake, clutch and accelerator pedals, the steering wheel, the steering column, a seat armrest, a cup holder, the mounting unit for a cellular telephone or another communications or computing device and the visors. Further,
Automobiles equipped with airbags are well known in the prior art. In such airbag systems, the car crash is sensed and the airbags rapidly inflated thereby insuring the safety of an occupation in a car crash. Many lives have now been saved by such airbag systems. However, depending on the seated state of an occupant, there are cases where his or her life cannot be saved even by present airbag systems. For example, when a passenger is seated on the front passenger seat in a position other than a forward facing, normal state, e.g., when the passenger is out of position and near the deployment door of the airbag, there will be cases when the occupant will be seriously injured or even killed by the deployment of the airbag.
Also, sometimes a child seat is placed on the passenger seat in a rear facing position and there are cases where a child sitting in such a seat has been seriously injured or killed by the deployment of the airbag.
Furthermore, in the case of a vacant seat, there is no need to deploy an airbag, and in such a case, deploying the airbag is undesirable due to a high replacement cost and possible release of toxic gases into the passenger compartment. Nevertheless, most airbag systems will deploy the airbag in a vehicle crash even if the seat is unoccupied.
For these reasons, there has been proposed a seated-state detecting unit such as disclosed in the following U.S. patents, which are incorporated herein by reference in their entirety to the extent the disclosure of these patents is necessary, assigned to the current assignee of the present application: Breed et al. (U.S. Pat. No. 5,563,462); Breed et al. (U.S. Pat. No. 5,829,782); Breed et al. (U.S. Pat. No. 5,822,707): Breed et al. (U.S. Pat. No. 5,694,320); Breed et al. (U.S. Pat. No. 5,748,473); Varga et al. (U.S. Pat. No. 5,943,295); Breed et al. (U.S. Pat. No. 6,078,854); Breed et al. (U.S. Pat. No. 6,081,757); and Breed et al. (U.S. Pat. No. 6,242,701). Typically, in some of these designs three or four sensors or sets of sensors are installed at three or four points in a vehicle passenger compartment for transmitting ultrasonic or electromagnetic waves toward the passenger or driver""s seat and receiving the reflected waves. Using appropriate hardware and software, the approximate configuration of the occupancy of either the passenger or driver seat can be determined thereby identifying and categorizing the occupancy of the relevant seat.
However, in the aforementioned literature using ultrasonics, the pattern of reflected ultrasonic waves from an adult occupant who may be out of position is sometimes similar to the pattern of reflected waves from a rear facing child seat. Also, it is sometimes difficult to discriminate the wave pattern of a normally seated child with the seat in a rear facing position from an empty seat with the seat in a more forward position. In other cases, the reflected wave pattern from a thin slouching adult with raised knees can be similar to that from a rear facing child seat. In still other cases, the reflected pattern from a passenger seat which is in a forward position can be similar to the reflected wave pattern from a seat containing a forward facing child seat or a child sitting on the passenger seat. In each of these cases, the prior art ultrasonic systems can suppress the deployment of an airbag when deployment is desired or, alternately, can enable deployment when deployment is not desired.
If the discrimination between these cases can be improved, then the reliability of the seated-state detecting unit can be improved and more people saved from death or serious injury. In addition, the unnecessary deployment of an airbag can be prevented.
In this regard, U.S. Pat. No. 6,411,202 (Gal et al.) describes a safety system for a vehicle including at least one sensor which receives waves from a region in an interior portion of the vehicle which thereby defines a protected volume at least partially in front of the vehicle airbag. A processor is responsive to signals from the sensor for determining geometric data of objects in the protected volume.
With respect to the adjustment of a vehicular seat, the adjustment of an automobile seat occupied by a driver of the vehicle is now accomplished by the use of either electrical switches and motors or by mechanical levers. As a result, the driver""s seat is rarely placed at the proper driving position which is defined as the seat location which places the eyes of the driver in the so-called xe2x80x9ceye ellipsexe2x80x9d and permits him or her to comfortably reach the pedals and steering wheel. The xe2x80x9ceye ellipsexe2x80x9d is the optimum eye position relative to the windshield and rear view mirror of the vehicle.
The eye ellipse, which is actually an ellipsoid, is rarely achieved by the actions of the driver for a variety of reasons. One specific reason is the poor design of most seat adjustment systems particularly the so-called xe2x80x9c4-way-seatxe2x80x9d. It is known that there are three degrees of freedom of a seat bottom, namely vertical, longitudinal, and rotation about the lateral or pitch axis. The 4-way-seat provides four motions to control the seat: (1) raising or lowering the front of the seat, (2) raising or lowering the back of the seat, (3) raising or lowering the entire seat, (4) moving the seat fore and aft. Such a seat adjustment system causes confusion since there are four control motions for three degrees of freedom. As a result, vehicle occupants are easily frustrated by such events as when the control to raise the seat is exercised, the seat not only is raised but is also rotated. Occupants thus find it difficult to place the seat in the optimum location using this system and frequently give up trying leaving the seat in an improper driving position
Many vehicles today are equipped with a lumbar support system that is never used by most occupants. One reason is that the lumbar support cannot be preset since the shape of the lumbar for different occupants differs significantly, i.e., a tall person has significantly different lumbar support requirements than a short person. Without knowledge of the size of the occupant, the lumbar support cannot be automatically adjusted.
As discussed in the above referenced ""320 patent, in approximately 95% of the cases where an occupant suffers a whiplash injury, the headrest is not properly located to protect him or her in a rear impact collision. Also, the stiffness and damping characteristics of a seat are fixed and no attempt is made in any production vehicle to adjust the stiffness and damping of the seat in relation to either the size or weight of an occupant, or to the environmental conditions such as road roughness. All of these adjustments, if they are to be done automatically, require knowledge of the morphology of the seat occupant.
Systems are now being used to attempt to identify the vehicle occupant based on a coded key or other object carried by the occupant. This requires special sensors within the vehicle to recognize the coded object. Also, the system only works if the coded object is used by the particular person for whom the vehicle was programmed. If the vehicle is used by a son or daughter, for example, who use their mother""s key then the wrong seat adjustments are made. Also, these systems preserve the choice of seat position without any regard for the correctness of the seat position. With the problems associated with the 4-way seats, it is unlikely that the occupant ever properly adjusts the seat. Therefore, the error will be repeated every time the occupant uses the vehicle.
Moreover, these coded systems are a crude attempt to identify the occupant. An improvement can be made if the morphological characteristics of the occupant can be measured as described below. Such measurements can be made of the height and weight, for example, and used not only to adjust a vehicular component to a proper position but also to remember that position, as fine tuned by the occupant, for re-positioning the component the next time the occupant occupies the seat. For the purposes herein, a morphological characteristic will mean any measurable property of a human such as height, weight, leg or arm length, head diameter etc.
As discussed more fully below, in a preferred implementation, once at least one and preferably two of the morphological characteristics of a driver are determined, e.g., by measuring his or her height and weight, the component such as the seat can be adjusted and other features or components can be incorporated into the system including, for example, the automatic adjustment of the rear view and/or side mirrors based on seat position and occupant height. In addition, a determination of an out-of-position occupant can be made and based thereon, airbag deployment suppressed if the occupant is more likely to be injured by the airbag than by the accident without the protection of the airbag. Furthermore, the characteristics of the airbag including the amount of gas produced by the inflator and the size of the airbag exit orifices can be adjusted to provide better protection for small lightweight occupants as well as large, heavy people. Even the direction of the airbag deployment can, in some cases, be controlled.
Still other features or components can now be adjusted based on the measured occupant morphology as well as the fact that the occupant can now be identified. Some of these features or components include the adjustment of seat armrest, cup holder, steering wheel (angle and telescoping), pedals, phone location and for that matter the adjustment of all things in the vehicle which a person must reach or interact with. Some items that depend on personal preferences can also be automatically adjusted including the radio station, temperature, ride and others.
Heretofore, various methods have been proposed for measuring the weight of an occupying item of a vehicular seat. The methods include pads, sheets or films that have placed in the seat cushion which attempt to measure the pressure distribution of the occupying item. Prior to its first disclosure in U.S. Pat. No. 5,822,707 referenced above, systems for measuring occupant weight based on the strain in the seat structure had not been considered. Prior art weight measurement systems have been notoriously inaccurate. Thus, a more accurate weight measuring system is desirable. The strain measurement systems described herein, substantially eliminate the inaccuracy problems of prior art systems and permit an accurate determination of the weight of the occupying item of the vehicle seat. Additionally, as disclosed herein, in many cases, sufficient information can be obtained for the control of a vehicle component without the necessity of determining the entire weight of the occupant. For example, the force that the occupant exerts on one of the three support members may be sufficient.
Most, if not all, of the problems discussed above are difficult to solve or unsolvable using conventional technology.
The use of pattern recognition, or more particularly how it is used, is important to some aspects of the instant invention. xe2x80x9cPattern recognitionxe2x80x9d as used herein will generally mean any system which processes a signal that is generated by an object (e.g., representative of a pattern of returned or received impulses, waves or other physical property specific to and/or characteristic of and/or representative of that object) or is modified by interacting with an object, in order to determine to which one of a set of classes that the object belongs. Such a system might determine only that the object is or is not a member of one specified class, or it might attempt to assign the object to one of a larger set of specified classes, or find that it is not a member of any of the classes in the set. The signals processed are generally a series of electrical signals coming from transducers that are sensitive to acoustic (ultrasonic) or electromagnetic radiation (e.g., visible light, infrared radiation, radar, or any other frequency), although other sources of information are frequently included.
A trainable or a trained pattern recognition system as used herein generally means a pattern recognition system which is taught to recognize various patterns constituted within signals by subjecting the system to a variety of examples. The most successful such system is the neural network. Thus, to generate the pattern recognition algorithm from returned waves, test data is first obtained which constitutes a plurality of sets of returned waves, or wave patterns, from an object (or from the space in which the object will be situated in the passenger compartment, i.e., the space above the seat) and an indication of the identity of that object, (e.g., a number of different objects are tested to obtain the unique wave patterns from each object). As such, the algorithm is generated, and stored in a computer processor, and which can later be applied to provide the identity of an object based on the wave pattern being received during use by a receiver connected to the processor and other information. For the purposes here, the identity of an object sometimes applies to not only the object itself but also to its location and/or orientation in the passenger compartment. For example, a rear facing child seat is a different object than a forward facing child seat and an out-of-position adult is a different object than a normally seated adult.
Other means of pattern recognition exist where the training is done by the researcher including Fuzzy Logic and Sensor Fusion systems.
To xe2x80x9cidentifyxe2x80x9d as used herein will generally mean to determine that the object belongs to a particular set or class. The class may be one containing, for example, all rear facing child seats, one containing all human occupants, or all human occupants not sitting in a rear facing child seat depending on the purpose of the system. In the case where a particular person is to be recognized, the set or class will contain only a single element, i.e., the person to be recognized.
To xe2x80x9cascertain the identity ofxe2x80x9d as used herein with reference to an object will generally mean to determine the type or nature of the object (obtain information as to what the object is), i.e., that the object is an adult, an occupied rear facing child seat, an occupied front facing child seat, an unoccupied rear facing child seat, an unoccupied front facing child seat, a child, a dog, a bag of groceries, etc.
An xe2x80x9cobjectxe2x80x9d or xe2x80x9coccupying itemxe2x80x9d of a seat may be a living occupant such as a human or a dog, another living organism such as a plant, or an inanimate object such as a box or bag of groceries or an empty child seat.
xe2x80x9cOut-of-positionxe2x80x9d as used for an occupant will generally mean that the occupant, either the driver or a passenger, is sufficiently close to the occupant protection apparatus (airbag) prior to deployment that he or she is likely to be more seriously injured by the deployment event itself than by the accident. It may also mean that the occupant is not positioned appropriately in order to attain the beneficial, restraining effects of the deployment of the airbag. As for the occupant being too close to the airbag, this typically occurs when the occupant""s head or chest is closer than some distance, such as about 5 inches, from the deployment door of the airbag module. The actual distance value where airbag deployment should be suppressed depends on the design of the airbag module and is typically farther for the passenger airbag than for the driver airbag.
xe2x80x9cTransducerxe2x80x9d as used herein will generally mean the combination of a transmitter and a receiver. In some cases, the same device will serve both as the transmitter and receiver while in others two separate devices adjacent to each other will be used. In some cases, a transmitter is not used and in such cases transducer will mean only a receiver. Transducers include, for example, capacitive, inductive, ultrasonic, electromagnetic (antenna, CCD, CMOS arrays), weight measuring or sensing devices.
xe2x80x9cAdaptationxe2x80x9d as used here represents the method by which a particular occupant sensing system is designed and arranged for a particular vehicle model. It includes such things as the process by which the number, kind and location of various transducers is determined. For pattern recognition systems, it includes the process by which the pattern recognition system is taught to recognize the desired patterns. In this connection, it will usually include (1) the method of training, (2) the makeup of the databases used for training, testing and validating the particular system, or, in the case of a neural network, the particular network architecture chosen, (3) the process by which environmental influences are incorporated into the system, and (4) any process for determining the pre-processing of the data or the post processing of the results of the pattern recognition system. The above list is illustrative and not exhaustive. Basically, adaptation includes all of the steps that are undertaken to adapt transducers and other sources of information to a particular vehicle to create the system that accurately identifies and determines the location of an occupant or other object in a vehicle.
Accordingly, it is a principal object of the present invention to provide new and improved arrangements and methods for adjusting or controlling a component in a vehicle. Control of a component does not require an adjustment of the component if the operation of the component is appropriate for the situation.
It is another object of the present invention to provide new and improved methods and apparatus for adjusting a component in a vehicle based on occupancy of the vehicle. For example, an airbag system may be controlled based on the location of a seat and the occupant of the seat to be protected by the deployment of the airbag.
It is another object of the present invention to provide new and improved arrangements and methods for controlling an occupant protection device based on the morphology of an occupant to be protected by the actuation of the device and optionally, the location of a seat on which the occupant is sitting. Control of the occupant protection device can entail suppression of actuation of the device, or adjusting of the actuation parameters of the device if such adjustment is deemed necessary.
Additional objects and advantages of this and other disclosed inventions include:
1. To provide a system for passively and automatically adjusting the position of a vehicle component to a near optimum location based on the size of an occupant.
2. To provide a system for recognizing a particular occupant of a vehicle and thereafter adjusting various components of the vehicle in accordance with the preferences of the recognized occupant.
3. To provide systems for approximately locating the eyes of a vehicle driver to thereby permit the placement of the driver""s eyes at a particular location in the vehicle.
4. To provide a pattern recognition system to permit more accurate location of an occupant""s head and the parts thereof and to use this information to adjust a vehicle component.
5. To provide a method of determining whether a seat is occupied and, if not, leaving the seat at a neutral position.
6. To provide a system for automatically adjusting the position of various components of the vehicle to permit safer and more effective operation of the vehicle including the location of the pedals and steering wheel.
7. To determine whether an occupant is out-of-position relative to the airbag and if so, to suppress deployment of the airbag in a situation in which the airbag would otherwise be deployed.
8. To adjust the flow of gas into and/or out of the airbag based on the morphology and position of the occupant to improve the performance of the airbag in reducing occupant injury.
9. To provide a system where the morphological characteristics of an occupant are measured by sensors located within the seat.
10. To provide a system and method wherein the weight of an occupant is determined utilizing sensors located on the seat structure.
11. To provide apparatus and methods for measuring the weight of an occupying item on a vehicle seat which may be integrated into vehicular component adjustment apparatus and methods which evaluate the occupancy of the seat and adjust the location and/or orientation relative to the occupant and/or operation of a part of the component or the component in its entirety based on the evaluated occupancy of the seat.
12. To provide vehicular seats including a weight measuring feature and weight measuring methods for implementation in connection with vehicular seats.
13. To provide vehicular seats in which the weight applied by an occupying item to the seat is measured based on capacitance between conductive and/or metallic members underlying the seat cushion.
14. To provide adjustment apparatus and methods that evaluate the occupancy of the seat and adjust the location and/or orientation relative to the occupant and/or operation of a part of the component or the component in its entirety based on the evaluated occupancy of the seat and on a measurement of the occupant""s weight or a measurement of a force exerted by the occupant on the seat.
15. To provide adjustment apparatus and methods that evaluate the occupancy of the seat by a combination of ultrasonic sensors and additional sensors and adjust the location and/or orientation relative to the occupant and/or operation of a part of the component or the component in its entirety based on the evaluated occupancy of the seat.
16. To provide adjustment apparatus and methods that reliably discriminate between a normally seated passenger and a forward facing child seat, between an abnormally seated passenger and a rear facing child seat, and whether or not the seat is empty and adjust the location and/or orientation relative to the occupant and/or operation of a part of the component or the component in its entirety based thereon.
17. To provide weight measurement systems in order to improve the accuracy of another apparatus or system which utilizes measured weight as input, e.g., a component adjustment apparatus.
18. To provide adjustment apparatus and methods that evaluate the occupancy of the seat without the problems mentioned above.
Further objects of the present invention will become apparent from the following discussion of the preferred embodiments of the invention.
Accordingly, in order to achieve one or more of the objects above, an arrangement for controlling a component in a vehicle based on contents of a passenger compartment of the vehicle comprises at least one wave-receiving sensor arranged to receive waves from the passenger compartment, a processing circuit coupled to the wave-receiving sensor(s) and arranged to remove at least one portion of each wave received by the sensor(s) in a discrete period of time to thereby form a shortened returned wave, and a processor coupled to the processing circuit and arranged to receive data derived from the shortened returned waves formed by the processing circuit. The processor generates a control signal to control the component based on the data derived from the shortened returned waves formed by the processing circuit.
The portion of the wave which is removed may be an initial wave portion starting from the beginning of the time period and/or an end wave portion at the end of the time period.
When multiple sensors are provided, a sensor driver circuit may be coupled to the sensors for driving the wave-receiving sensors and a multiplex circuit coupled to the sensors for processing the waves received by the wave-receiving sensors. The multiplex circuit is switched in synchronization with a timing signal from the driver circuit.
A band pass filter may be interposed between the sensor and the processing circuit for filtering waves at particular frequencies and noise from the waves received by the at least one wave-receiving sensor. An amplifier may be coupled to the band pass filter to amplify the waves provided by the band pass filter and an analog to digital converter (ADC) may be interposed between the amplifier and the processing circuit for removing a high frequency carrier wave component and generating an envelope wave signal.
Another arrangement for controlling a component in a vehicle based on contents of a passenger compartment of the vehicle comprises a generating device for generating a succession of time windows, a receiving device for receiving waves from the passenger compartment during the time windows, a processing circuit coupled to the receiving device and arranged to remove at least one portion of each wave received by the receiving device in each time window to thereby form a shortened wave, and a processor coupled to the processing circuit and arranged to receive data derived from the shortened waves formed by the processing circuit. The processor generates a control signal to control the component based on the data derived from the shortened waves formed by the processing circuit. The same variations of the above-described arrangement may be used for this arrangement as well.
A method for controlling a component in a vehicle based on contents of a passenger compartment of the vehicle in accordance with the invention comprises the steps of receiving waves from the passenger compartment, removing at least one portion of each received wave in a discrete period of time to thereby form a shortened wave, deriving data from the shortened waves, and generating a control signal to control the component based on the data derived from the shortened waves. The variations of the above-described arrangement may be used for this method as well.
Another method for controlling a component in a vehicle based on contents of a passenger compartment of the vehicle comprises the steps of generating a succession of time windows, receiving waves from the passenger compartment during the time windows, removing at least one portion of each received wave in each time window to thereby form a shortened wave, deriving data from the shortened waves, and generating a control signal to control the component based on the data derived from the shortened waves. The variations of the above-described arrangement may be used for this method as well.
A method for generating an algorithm capable of determining occupancy of a seat in accordance with the invention comprises the steps of mounting a plurality of wave-receiving sensors in the vehicle, obtaining data from the sensors while the seat has a particular occupancy, forming a vector from the data from the sensors obtained while the seat has a particular occupancy, repeatedly changing the occupancy of the seat and for each occupancy, repeating the steps of obtaining data from the sensors and forming a vector from the data, modifying the vectors by removing at least one portion of the wave received by each sensor during a discrete period of time, and generating the algorithm based on the modified vectors such that upon input from the sensors, the algorithm is capable of outputting a likely occupancy of the seat. The modified vectors may be normalized prior to generation of the algorithm.
The modified vectors may be input into a compression circuit that reduces the magnitude of reflected signals from high reflectivity targets compared to those of low reflectivity. Further, a time gain circuit may be applied to the modified vectors to compensate for the difference in sonic strength received by the sensors based on the distance of the reflecting object from the sensor.
Modification of the vectors may entail removing an initial portion of the wave during the time period and/or removing an end portion of the wave during the time period.
The data may be obtained from sensors other than wave-receiving sensors including weight sensors, weight distribution sensors, seat buckle sensors, etc.